In monitoring and/or analyzing fetal contractions, externally applied devices (e.g., tocodynamometers) and intrauterine devices have been used. Regarding intrauterine pressure monitoring, catheters are typically inserted directly into the uterus (e.g., after the amniotic membranes have been broken). Once a catheter has been inserted in the uterus, a pressure measurement is taken by the catheter. The measured pressure is then transferred from the catheter (either electrically or mechanically depending on the type of catheter) to an interface cable. The interface cable then electrically transfers the pressure in the form of an electrical signal to one or more fetal monitors. A number of pressure catheter components and systems are described in U.S. Pat. No. 5,566,680 to Urion et al., the contents of which are incorporated in this application by reference.
Often, it becomes desirable to “zero” or “re-zero” the pressure catheter in situ. For example, a pressure catheter may include a pressure transducer that is “zeroed” to ensure that an output of the pressure transducer may be accurately compared to a reference value. Many conventional pressure catheters do not allow for a zeroing operation to be performed in situ. Further, the pressure catheters that do provide for such a zeroing operation suffer from a number of deficiencies. For example, in certain systems, a user depresses and holds a button on an interface cable, and then (while continuing to hold the button in a depressed state) zeroes the system through a mechanism provided on a fetal monitor. Such an operation is inconvenient because the user holds the button on the interface cable with a first hand and operates the zeroing mechanism on the fetal monitor with the other hand. Further, the user has no efficient way of knowing if the system is ready for the zeroing process to be performed.
Additionally, it is often desirable to confirm the functionality of the interface cable used in conjunction with an intrauterine pressure monitoring system. In certain conventional intrauterine pressure monitoring systems, a user follows a relatively complex multi-step process before referring to a screen of a monitoring system in order to verify if the interface cable is functioning properly. By their nature, such conventional procedures undesirably have a number of sources of potential error (e.g., errors in following a complex multi-step procedure, human error in determining if the screen indicates that the cable is functioning properly, etc.).
Thus, it would be desirable to provide an interface cable that overcomes one or more of the above-described deficiencies.